Underground drilling systems are used to define a borehole in an earthen formation. During drilling the borehole, it is desirable to measure certain properties related to the formation, or the condition of the drilling operation downhole, and transmit that information to the surface for further analysis and/or automatic adjustment of drilling parameters if needed. Measurement while drilling (MWD) and logging-while-drilling (LWD) tools are types of drilling tools used downhole to obtain and transmit drilling data to the surface. Some MWD and LWD tools are electromagnetic (EM) telemetry tools that are configured to generate an electromagnetic field that passes into the formation and propagates to the surface. At greater depths in the bore, the EM field signal attenuation and noise can limit meaningful signal detection or prevent detection altogether